Northrop Grumman Electronic — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation 400 Seventh St., S.W. Special Programs Research and Washington, D.C. 20590 Administration MAR 3 0 2004 Mr. Steven McKew Manger, Compliance Engineering Ref No.: 04-0047 Northrop Grumman Electronic P. O. Box 746, Mail Stop 1401 Baltimore, MD 21203 Dear Mr. McKew: This is in response to your letter dated February 25, 2004, concerning the requirements for measuring levels of radioactive contamination on the external surfaces of packages of radioactive material offered for transportation under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-181). Section 173.443(a) requires the level of non-fixed (removable) radioactive contamination on the external surfaces of a package offered for transportation to be kept as low as reasonably achievable. The HMR prohibit the non-fixed radiation contamination to exceed the limits set forth in Table 11 and authorize the use of a wipe survey or other assessment method to check for non-fixed radioactive contamination. The use of wipes is a suggested technique; however, there is no specification for the type of instrument to be used to measure the amount of activity on the wipe. The regulations permit other methods to be used to assure that contamination is within acceptable limits. The HMR provide shippers considerable flexibility to determine the most appropriate method among recognized procedures to achieve the performance standard. I hope this information is helpful. Please contact us if you require additional assistance Sincerely, Chief, Regulations Development Office of Hazardous Materials Standards 173.443 040047 0: 2600т."#

Page 2Relertova $173.443 RAM 04-0047 NORTHRO, GRUMMAN Electronic System February 25, 2004 Mr. Edward T. Mazzullo Director, Office of Hazardous Materials Standards 400 7' Street, S.W. Research and Special Programs Administration Washington, D.C. 20590-001 radioactive material (HMR; 49CFR Part 173.44) Subject: Clarification concerning contamination control of external packages containing Dear Mr. Mazzullo, Northrop Grumman Electronic Systems has historically shipped an electronic component that contains trace quantities of a radioactive isotope. We currently ship this as "Radioactive material, excepted package-instruments or articles, UN2911" Our manufacturing process takes a small glass ampule slightly larger than the size of your average pill capsule. This ampule has a trace amount of radioactive material sealed inside what we deem an electronic tube. Once sealed, we wipe/smear and ensure no external contamination electronic tube connected to additional electronics and further encased within a sealed metal exists on the external surface of the ampule/tube. Our manufacturing process then has the housing. At this point in the manufacturing process, the external surfaces are again smeared to ensure there is no external contamination on the surface of the sealed metal housing. As a , VCR tape. At this level of assembly, all requirements for labeling are verified, and there is a eference, once it is incorporated in the larger assembly, the approximate size of the unit is that of zero radiation reading on all surfaces. The unit is then cleared by our radiation safety procedures as to not posing any handling hazard, not possessing any surface contamination, and not having any surface readings. At this point the unit is moved to the shipping department for transportation to another facility for incorporation into a larger electronic component.#

Page 3Page 2 My question involves our interpretation of 49CFR 173.443, and if that interpretation would require wipe testing of the surface on the box being shipped to our other facility, or can we utilize of contaminated pete. our operatio at the to previous there ts che surpain cos minicatio at t contamination control. Our operational to ensure the unit never leave the manufacturing area with any reading of radioactivity, and two key manutacturing points, and then release the sealed unit as free and clear. Our approach is always with zero surface contamination, fixed or smearable. I liken this analysis to that of smoke detectors, and a case of detectors being readied for shipment. I greatly appreciate your assistance in this manner, and look forward to your response. Steven McKew Manager, Compliance Engineering Northrop Grumman Electronic Systems P.O. Box 746, Mail Stop 1401 Baltimore, MD 21203 Ph (410) 993-8940 Fx (410) 993-2753 Cell (410) 227-6399#